Cages of this type position the rollers against the race and hold them there in relation to one another and to the bearing system. They also prevent the individual rollers from coming into contact.
German Patent 1 007 570 discloses making such cages in the form of binary windowed cages. Such cages consist of a strip of metal with recesses, each with a plastic window in it. The windows have a collar that rests against the metal strip. One drawback to such cages is that they require an additional guide to position the strip in the race system when they are used in large roller bearings in axial races. Metal slides on the strip are usually employed for this purpose, especially in large roller bearings.